Attribution is the process of identifying a set of user actions (“events”) that contribute in some manner to a desired outcome, and then assigning value to each of these events.

In digital advertising, attribution is traditionally done at a user-specific level, where a consistent user identifier can be established across all analyzed events. In traditional media, attribution is generally done at the macro, user-group level, as there is no consistent user identifier available. The focus of this document is user-specific attribution, but it will also reference user-group attribution in order to highlight the challenges of integrating data across mediums.